Question: A box contains $4$ red marbles, $5$ green marbles, and $5$ blue marbles. If a marble is randomly chosen, what is the probability that it is not blue?
Solution: There are $4 + 5 + 5 = 14$ marbles in the box. There are $5$ blue marbles. That means $14 - 5 = 9$ are not blue. The probability is $ \frac{9}{14}$.